Embodiments relate to a predictor device for controlling at least one actuating variable of a plant having at least one actuator, which can be controlled by the actuating variable, and a state with at least one controlled variable that can be detected by a sensor. The predictor has an adaptation device and an L1-adaptive control apparatus. The predictor has a state modelling device for estimating a behavior of the plant and outputs an estimated state with at least one estimated variable. The embodiments relate to an aircraft with such a control device for flight control. The embodiments also relate to an L1-adaptive control method using an L1-adaptive control apparatus, an adaptation device generating a matched uncertainty signal and an unmatched uncertainty signal, and a predictor having a state modelling device. The embodiments relate to an aircraft with a control device for flight control, which executes such a method.